A plane can fly 315 mph in still air. If it can fly 190 miles downwind in the same amount of time it can fly 125 miles upwind, find the velocity of the wind.

Question

Math

Answer 1

(A) Establish (315 + W) Miles Per Hour × T Hours Equals 190 Miles.

(B) Establish (315 − W) Miles Per Hour × T Hours Equals 125 Miles.

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Adding (A) to (B) gives 630 Miles Per Hour x T Hours Equal to 315 Miles

or T = 0.5 Hours.

With T equal to 0.5 Hours, take from (A) that (315 + W) MPH × (0.5) H = 190 M or

(157.5 + 0.5W) M = 190 M or Wind Velocity equals (190 −157.5) M Divided By 0.5 H.

This last simplifies to 2 × 32.5 or 65 Miles Per Hour.

Then confirm that:

(315 + 65) MPH × 0.5 H = 190 M.

(315 − 65) MPH × 0.5 H = 125 M.